Zig-zag sewing machine with variable sewing cycle



Sept. 19, 1961 A. MORO 3,000,333

ZIG-ZAG SEWING MACHINE WITH VARIABLE SEWING CYCLE Filed July 29, 1955 4 Sheets-Sheet 1 FIG.

Inventor A ttorn eys aaiw Sept. 19, 1961 A. MORO 1 3,000,333

ZIG-ZAG SEWING MACHINE WITH VARIABLE SEWING CYCLE Filed July 29, 1955 4 Sheets-Sheet 2 I 1 /7\ F r LL Inventor 7-0/|//o Mafia A itorneys A. MORO Sept. 19, 1961 4 Sheets-Sheet 3 Filed July 29, 1955 Qbu Attorney:

A. MORO Sept. 19, 1961 ZIG-ZAG SEWING MACHINE WITH VARIABLE SEWING CYCLE Filed July 29, 1955 4 Sheets-Sheet 4 m m U n I mm m t QN 0 O O O x nkee 0 W m g QR um K mm ww United States Patent 3,000,333 ZIG-ZAG SEWING MACHINE WITH VARIABLE SEWING CYCLE Antonio Moro, Milan, Italy, assignor to F.1li Borletti S.p.A., Milan, Italy Filed July 29, 1955, Ser. No. 525,177 Claims priority, application Italy Aug. 6, 1954 13 Claims. (Cl. 112-158) The present invention relates to a zig-zag sewing machine, wherein the zig-zag sewing cycle can be varied at will, independently of the stitch adjustment, which can be effected by hand in the course of any chosen cycle.

It is matter of a machine of the kind in which the cross movement for forming the zigzag stitch is transmitted to the needle bar which receives its reciprocating up and down movement from a crank mechanism driven by the main shaft, by means of a rod connected to a shaft sliding within a support caused to swivel, through a lever, by a cam driven by the same main shaft, said support and the shaft sliding in said support being able to be adjusted in their setting with respect to the rod, for respectively regulating the cross origin of the zigzag stitch and the amplitude of the latter by means of two corresponding mechanisms driven by hand.

The machine according to the invention is characterized by the combination of means allowing for the application, beside the usual cam and on its shaft, of a removable cam responding to a determined zig-zag sewing cycle, with a mounting of the lever driving the oscillating support such as to allow said lever to be displaced from the usual cam to the removable cam by sliding on its rotating pin, without displacing said support.

Of course, the machine can also be arranged for rectilinear sewing, this being obtained, in a known manner, by shifting the shaft sliding in the oscillating support and carrying the pivoting center of the rod actuating the needle bar, so as to bring said pivoting center in coinci dence with the oscillation center of said support. The rod arranged in the above manner does not receive any movement when both the lever driven by the cam and the support caused to oscillate by said lever, are moved, so that the needle bar is not transversely displaced during its reciprocating movement.

Under these conditions, however, on one hand the continuous free oscillation of both the lever and the oscillating support during the rectilinear sewing operation increases the wear of the members unnecessarily in motion, and on the other hand either on account of a possible lacking precision of the assembly in mounting or setting the control drives or in consequence of the plays produced in the members by the wear, the oscillating lever and the support driven by said lever may transmit to the needle bar slight oscillations depending on said imperfections, causing thus irregularities in the rectilinear path of the seam. I

These drawbacks are fully eliminated by means of a modification forming also the object of the present invention of both the device designed to effect the displacement of the oscillating lever and the setting positions that can be taken up by said lever.

The modification consists in that the machine, besides the two cams, also carries as a bearing for the oscillating lever, a member formed so as to leave still the lever bearing thereupon and in that means adapted to be controlled from outside of the frame are provided for setting the oscillating lever either on one or the other of said cams or on the member which 'makes it remain at a standstill, according to the case. 1 t

The bearing member making the lever remain at a standstill can be, for example, a cylinder with smooth "ice surface mounted on the same shaft of the cams, or a simple plane surface arranged on the machine and independent of said shaft.

As to the means for displacing and setting in place the oscillating lever, it consists in a pushing device acting on a sleeve rigidly connected to said lever and apt to slide on the rotation pin thereof, having a suitable length, said device being combined with one or more springs apt to co-operate therewith for exactly establishing the lever in the required position.

The annexed drawings show various embodiments of the machine according to the invention.

In said drawings:

FIG. 1 is a longitudinal section of the machine;

FIG. 2 is a cross section of said machine according to the broken line A-A of FIG. 1;

FIG. 3 is a partial cross section of the machine according to the line BB of FIG. 1;

FIG. 4 shows in plan view a simple means for displacing and guiding the lever for driving the oscillating support from the usual cam to the other cam and vice versa.

FIG. 5 shows the zigzag stitch on the three starting positions which can be obtained by adjusting the setting of the oscillating support. 7

FIG. 6 is a plau' view, partly in section, of an embodiment of the modification of the invention for the displacing device of the oscillating lever and the positions of putting in place that said lever can receive;

FIG. 7 is a side view of this embodiment;

FIG. 8 shows a detail of the maneuvering handgrip of the displacing device of the oscillating lever according to FIGS. 6 and 7;

FIG. 9 shows in plan view, partly in section, a further embodiment of said modification;

FIG. 10 is a side view of an embodiment according to FIG. 9.

As shown in FIGS. 1 to 3, the shaft 1, which in known manner can be driven either by motor or pedal, is mounted in the upper portion of the frame 2 of the machine. By means of the crank pin 3 and the connecting rod 4 it imparts the vertical reciprocating movement to the needle bar 5. The crank 6 of the shaft 1 imparts the reciprocating motion to the connecting rod 7, which, on its turn, through the lever 8, the shaft 9 and the pair of toothed bevel wheels 10, causes the oscillation of the hook 11. Thus, by the combination of the reciprocating movement of the needle 12, carried by the bar 5, and of the oscillation of the hook 11, the stitch formation can be formed in known manner.

The shaft 1 carries the worm 13 engaging with the worm Wheel 14 secured onto the shaft 15 at right angles to the shaft 1. Worm 13 and wheel 14 are proportioned in such a manner as to cause the shaft 15 to turn at a lower speed than the shaft 1 according to a suitably established ratio. On the front portion of the shaft 15 the cam 16 is secured. Against the periphery of this cam bears the end-'18 of the lever 19 pivoted on the shaft 2!, the adherence of the end 18 on the surface 17 being assured by the spring 21. To the lever 19 is rigidly connected the arm 22 having a forked end 23 which engages the pin 24 carried by a support 25 which is pivotally mounted on a pin 26 carried by the support 35, the latter being pivotally mounted on the pin 35' (FIG. 2). The support 25 has two arms 27 and 28 which are provided with coaxial holes 27 and 28' wherein can slide the shaft 29 upon which the forked end 30 of a rod 31 is centrally pivoted. The other end of rod 31 is pivoted on a projection of the support 32 of the needle bar 5. This support is connected to the frame 2 in 33 by means of the small elastic plate 34. The zig-zag formation of the stitch depends on the oscillation imparted to the 3 support 32 by the rod 31 under the action of the lever 19 driven by the cam 16.

The support 35 pivoted on the pin 35' is prolonged into a lower arm 36 having a forked end.37, which embraces a cylindrical projection of a piece 39 pivoted on 40. To the piece 39 is secured the elastic plate 41, which at its upper end carries the handling button 42.

On the pin 43 of the fork 30 is pivoted the link 44, which at its lower end is pivoted on the pin 45 of the sleeve 46. This sleeve is provided with an arm 47 upon which the pin 48 with button 49 is mounted.

By means of this arrangement, by maneuvering the button 49, on the pin 48 such an action is exerted by means of the sleeve 46 and the link '44 that a sliding of the shaft 29 in the support 25 takes place. The pin 43 in consequence of said sliding displaces'itself with respect to the oscillating pin 26. The amplitude of the zig-zag stitch depends on this displacement, as, while the fork 30 and consequently the rod 31' are not displaced when the axis of the pin 43 coincides with the axis of the pin 26, the eccentricity of the pin 43'with respect to 26causes the oscillation of 31, this oscillation increasing with the increase-of said eccentricity. The surface 17 of the cam 16 is formed in such a manner that the cross displacement of the needle bar may be in synchronism with the axial displacements of said bar. There will thus be obtained a stitch at the right and a stitch at the left when the needle bar is regulated for zig-zag sewing, and the rectilinear sewing when said bar is accordingly adjusted.

The transversal origin of the zig-zag stitch is established by the button 42, by means'of'which, through the plate 41, the piece39, the arm 36 and the support 35, the position of the support 25 is caused to vary at small angles by fixing the pin 26 of said support generally in one of the three positions: central, to the right and to the left. There willthus be respectively obtained: the central rectilinear sewing, or the zigzag sewing symmetric with respect to the central right line (FIG. 5a); the rectilinear sewing to the left or the zig-zag sewing with origin to the left (FIG. 5b); and the rectilinear sewing to the right or the zig-zag sewing with origin to the right (FIG. 50).

The cam 16 is employed only for the common zig-zag sewing with hand adjustment and control of both the zig-zag amplitude and its origin.

To the cam 16 there can be coupled a second removable cam, said second cam being mounted on the same shaft of the cam 16 or, preferably, on its hub. This second cam 50 is shaped for a deter-mined cyclically varying of the zigzag sewing. When'it-is desired to place cam 50in operation, the end 18 of the lever 19 is brought into contact with the periphery 51 by displacing it from the surface 17 of the cam 16, which thus remains inoperative. The transfer of the lever 1819 from the cam 16 to the cam 50 is obtained by causing the piece 19-22 to axially slide on the shaft 20 by means, inthe embodiment shown in FIGS. 1 to 4, of a button 52 fixed on the lever 19. A pin 53, carried by the hub of the piece 1922 is engaged in a slot 54 with notches of a plate 55 fixed to the frame 2 so that for passing from the first cam to the second one, the lever 19 must at first be caused to turn in order to be removed from the first cam, then be caused to axially slide and at last caused to come into contact with the second cam, on which it is maintained in contact therewith by the spring 21. The fork 23 remains always engaged with the pin 24, the latter having a length sufiicient for allowing the sliding of the piece .19 22.' If it is desired to exclude the, second cam and to return to the first one, the button 52 will be operated in the reverse manner.

When the lever 19 is driven by the second cam 50, the zig-zag stitch follows the profile of this cam during the complete revolution of the latter and at each successive revolution of said cam the same series of stitches, as

they have been established, is repeated. If, for instance, between the worm 13 and the wheel 14 such a ratio has been established that the cam may effect one revolution for each twenty revolutions of the main shaft 1, the needle can take up in the cross direction up to twenty different positions (one for each stitch) during one revolution of the cam, this cycle being continuously repeated. The cam 50 can be easily removed and substituted by any other cam for a different type of sewing. by unscrewing the knurled button 56. A spring 57 (FIG. 3) serves to facilitate the removal of the cam 50 from the cam 16, when the button 56 is unscrewed, in order to substitute said cam 50 with a cam of any other type.

For effecting all these operations of substitution of the cams and sliding of the lever 19 from one cam to the other one, cams and levers can be reached through a window covered by the plate 58, said window being arranged on the side of the machine frame facing the said cams.

For manually adjusting the oscillation amplitude of the zigzag stitch, the button 49, as previously stated, is made use of.

For convenience of the operator, when stitches of limited width are to be made at intervals at will, the movement of the button 49 can be limited by arranging suitable stops 59 located in the desired position in the window in which the button 49 slides; said stops are blocked each by a button 60 with threaded stem screwed in projections of said stops. The stem 48 of the button 49 having the portion 61 of greater diameter is held in a predetermined position by a stop 59. By axially pushing, however, the button 49 against the action of the spring 62 towards the interior of the frame, the portion 61 is removed from the stops and the portion '63 of smaller diameter moves freely by said stops, allowing thus the button 49 to effect its complete movement as if no stops were provided. Thus, ,even if the stops are left fixed in a determined position, it. is always possible to adjust the button in any desired manner.

Beside the two positions on the cams 16 and St the lever 18, 19, can, according to a modificaton of the present invention, also receive a third position independent of the cams and determined by a member on which the lever remains at a standstill, that is, it is not subjetced to any oscillation, said member being formed by a disk 79 coaxial with the cams 16 and 50.

To this end, in the embodiment of this modification according to FIGS. 6 to 8, the sleeve 64, rigidly connected to the lever 19 and adapted to slide on the shaft 20, has a groove 65 within which pin 66 carried by the small lever 67 mounted on the bushing 68 is maintained, the latter being pivoted on the pin 69.

On the bushing 68 is loosely mounted a bell crank lever, one arm 70 of which is lying upon the small lever 67, and the other arm 71 of which is terminated, in a position accessible to the operator, by a hand grip 72 adapted to be handled by the latter. The arm 71 is suitably elastic and it is bent in such a manner as to slightly bear on the lower surface of the small bridge 73.

This bridge 73 has three notches (or holes) 74a, b, c; the projection 75 formed on the upper side of the lever arm 71 can penetrate into one or another of said notches, so that the lever 7071 remains locked in one of these three positions. The lever 67 is maintained in phase with the arm 70 of the lever 70-71, by the two ends, suitagy bent, of the spring 76 wound about the bushmg The operation of the device is as follows: 7

If the lever 18, 19, 22 is on the cam 16 and it is desired to transfer it onto the cam 50, it is sufiicient to slightly press, according to the arrow 76, the hand grip 72, so as to cause the projection 75 to come out of the central hole 74b, and then to displace said hand grip according to the arrow 77, by leaving it free, when the projection 75 is in register with the hole 74a. As a result of the-elasticity of the arm 71, the projection 75 enters then-into the hole 74a, locking the lever 18, 19, 22 in this position.' If the end 18 of the lever 19 finds the way free, that is a space of the cam 50, the lever 19, having no obstacle, slides together with the sleeve 64 on the shaft 20, according to the arrow 78, said sleeve being pushed in this direction by the pin 66, the lever 67- of which is moved by the end 76a of the spring 76, together with the lever arm 70. If, on the contrary, the end 18 finds, in this moment, a projection of the cam 50, said projection causing said end to stop, the lever 70, 71 can still be moved, but the pin 66 and the lever 67 remain stopped locking thus the end 76a of the spring 76, while the other end 76b of the spring 76 displaces itself together with the arm 70, increasing the charge of the spring 76 and the pressure of the end 76a on the lever 67. When, however, the cam 50 has turned more than one step, the end 18 will be, in a given moment, in the uppermost position 18, so that it will be able to move adjacent the periphery of cam 50, which in this position has a radius smaller than or at most like that of the cam 16 for the same angular position. The transfer, under these conditions, is caused by the end 76a of the spring 76, which, having a suificient charge, pushes the small lever 67 in the normal position corresponding to that of the arm 70.

The same operation is obtained when the lever 71 is moved into register with the hole 7411 or 740. The lever 18, 19 will then be moved into contact with the cam 16 or the member 79, respectively. The member 79 in the shown example is a cylinder rotating wtih the cams.

Referring to the embodiment of FIGS. 9 and 10, it can be seen that with the shaft 20 there is a coaxial shaft 20, on which is mounted a sleeve 64'. The shaft 20' rotates in bearings formed on the frame 2 of the machine, while it is prevented from axial displacement by a button 72 and a ring 80 mounted thereon on the outside and inside of frame 2, respectively.

The sleeve 64 of the lever 18, 19, 22 carries a projection having the form of a tooth or pin 66', which is kept always in contact with the surface 65' of the sleeve 64 by the spring 76'a. This sleeve can slide on the shaft 20' and has a length corresponding to the greatest displace ment of the lever 19 for passing from the first cam to the cylindrical member 79, which leaves lever 19 stationary, but it cannot turn on the shaft 20 due to a pin 81 arranged in the slot 82 thereof. 'The right hand end of the slot 82 is kept in contact with the pin 81 by the spring 76'a, which is stronger than the spring 76b. The periphery 65' is shaped in such a manner that starting from a fiat portion 65a of periphery 65' there follows an inclined portion 6S'b, the latter being followed by a flat portion 65c, to which an inclined portion 65'd and a fiat portion 65'e follow, in sequence.

The axial distance between the flat portions of sleeve 64' is equal to the distance between the cams.

The operation of the device is as follows.

If the lever 19 bears on the cam 16, it means that it is in this position because the pin 66 is bearing against the flat portion 65'c. If it is desired to transfer said lever onto the cam 50, the button 72 is rotated according to the arrow 77; the sleeve 64' turns with this button and the inclined surface 65'd pushes according to the arrow 78 the pin 66' and consequently the lever 19. If this lever is stopped by a projection of the cam 50, the sleeve 64' retrocedes overcoming the resistance of the spring 76'a, but when the end 18 comes in register with a space of the cam 50 in consequence of the rotation of said cam, the lever 19 displaces itself according to the arrow 78 because of the spring 76'a, which, as it is stronger, overcomes the resistance of the spring 7615.

The button 72' has three positions in the revolution cycle, each of them defined by a snapping stop, not shown in the drawings. Each position corresponds to the coincidence of the pin 66 with one of the surfaces 65'a, 65'c, 65'e, that is to one of the three positions of the lever 19, 18. The lever operates in accordance with that described in the embodiment according to FIGS. 6 to 8.

It is thus sufiicient to turn the button 72 in such a manner as to bring it in the desired position so that the lever 18, 19 will automatically come into contact with the desired cam.

Likewise, there can be effected the displacement of the lever 19 in the direction opposite to that of the arrow 78 for causing said lever to pass from the cam 50 onto either the cam 16 or the bearing member 79.

It appears clear that the details, of the difierent characteristic. devices of the invention can vary from the ones shown in the annexed drawings and above described, without the invention passing out of the scope of the present description.

It must beyobserved, on the other hand, that, instead of one or the other of both arrangements for displacing and setting in place the oscillating lever, shown in FIGS. 6 to 10 and above described by way of example,'any whatever other arrangement can be employed, which may be adapted to reach the same aim, remaining still within the basic principle of these described arrangements.

What I claim is:

1. A zig-zag sewing machine comprising a frame, a main shaft, a needle bar, means operatively connected to said main shaftand needle bar to impart vertical oscillatory motion to said needle bar, an oscillating support,

a generally horizontal rod pivotally connected to one end of said needle bar and at its other end to said oscillating support, a first cam rotatably mounted in said machine on a camshaft, means for rotating said camshaft from said main shaft, a lever carried on a lever shaft having one end engaging said cam and the other end engaging verse movement of said needle bar, adjustable means connected to said support to rotate said support to vary the origin of the zig-zag stitch, a second cam removably mounted coaxially on a hub of said first cam, a spring being mountedbetweenthe two cams to thereby facilitate the removal of the removable cam when it is necessary .to substituteit with any other cam, a knurled button screwed on the shaft of the cams to retain said removable cam, and means for shifting said lever axially of the lever shaft for engaging either of said cams,

2. Ziz-zag sewing machine as claimed in claim 1, and further comprising an external wall having a small window shut by a plate facing said cams, said window permitting access to the interior of the frame for mounting or removing the removable cam.

3. A sewing machine as in claim 1, said oscillating support having two arms, said first adjustable means comprising two holes in said arms, a shaft slidable in said holes, linkage means for axially displacing said lastmentioned shaft, and a control button exteriorly of said frame connected to said linkage means for actuation thereof.

4. A sewing machine as in claim 3, an axially removable stem supporting said control button, and a spring urging said control button away from said frame.

5. Zig-zag sewing machine as claimed in claim 4, wherein the sliding stem of the button for adjusting the position of the latter-mentioned shaft has two zones with different diameters and said sewing machine has stop means in juxtaposition therewith for limiting the stroke of said stem when the zone having the greater diameter is in correspondence with said stop means.

6. A zig-zag sewing machine comprising a frame, a main shaft, a needle bar, means operatively connected to said main shaft and needle bar to impart vertical oscillatory motion to said needle bar, at oscillating support, a generally horizontal rod pivotally connected to one end of said needle bar and at its other end to said oscillating support, a first cam rotatably mounted in said machine on a camshaft, means for rotating said camshaft from said main shaft, a lever carried on a lever shaft having one end engaging said cam and the other end engaging said support for imparting oscillatory movement to said support, adjustable means connected to saidsupport for varying the amplitude of the oscillatory movement imparted by said support to said rod for varying the transverse movement of said needle bar, adjustable means connected to said support to rotate said support to vary the origin of the zigzag stitch, a second cam removably mounted coaxially on a hub of said first cam, a'spring being mounted between the two cams to thereby facilitate the removal of the removable cam when it is necessary to substitute it with any other cam, a knurled button screwed on the shaft of the cams to retain said removable cam, a cam-like member of zero amplitude mounted in said machine, and means accessible from the exterior of the machine frame for setting said lever either on anyof said cams and said cam-like member.

7. Zig-zag sewing machine as claimed in claim 6, wherein the cam-like member is a cylinder with smooth surface mounted on the same shaft as the cams.

8. Zig-zag sewing machine as claimed in claim 6, wherein the cam-like member comprises a plane surface on the machine and independent from the shaft of the cams.

9. A zig-zag sewing machine comprising a frame, a main shaft, a needle bar, means operatively connected to said main shaft and needle bar to impart vertical 8 necessary to substitute it with any other cam, a knurled button screwed on the shaft of the cams to retain said removable cam, a cam-like member of Zero amplitude mounted in said machine, a pushing device acting on a first sleeve rigidly connected to said lever and adapted to slide on the lever shaft, and a second sleeve coaxial with said first sleeve and mounted for sliding movement only on a rotatable driving shaft acting on said second sleeve and opposing the movement thereof, said second oscillatory motion to said needle bar, an oscillating support, a generally horizontal rod pivotally connected to one end of said needle bar andat its other end to said oscillating support, a first cam rotatably mounted in said machine on .a camshaft, means for rotating said camshaft from said main shaft, a lever carried on a lever shaft having one end engaging said cam and the other end engaging said-support for imparting oscillatory movement to said support, adjustable means connected to said support for varying the amplitude of the oscillatory movement impaitedby said support to said rod for varying the'transversemove'ment of said needle bar, adjust: able means conneotedto said support to rotate said support to vary the origin of the zig-zag stitch, asecond cam removably mounted coaxially on a hub of said first cam, a spring being mounted between the two cams to thereby facilitate the removal of. the removable oamrwhen it is sleeve eifecting its action on a pin axially carried by said first sleeve by means of the front surface thereof, said front surface having axially spaced pin-engaging surface thereabout. V g

l0. Zig-Zag sewing machine as claimed in claim 9,

further comprising another pin fixed on the driving shaft and prisoner in a slot of the second sleeve whereby the second sleeve is kept adherent to the other pin by the spring opposing its sliding movement. 1 1..Zig-zag sewing machine as. claimed in.claim 9, wherein the shaft driving the second'sleeve has a control member accessible to the operator, said member having three positions defined by three snapping stops.

l2. Zig-Zag sewing machine as claimed in claim 9, wherein the sleeve connected to the lever driving the oscillating support is urged by a spring opposed by the spring acting on the second sleeve, said spring urging the first sleeve keeping the axial pin of said first sleeve adherent to the second sleeve.

13. Zig-zag sewing machine as claimed in claim 12, wherein the spring acting on the sleeve connected to the lever driving the oscillating support is weaker than the opposed spring acting on the second sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,470,687 'Clarke Oct. '16, 1923 2,297,197 Bolter Sept. 29, 1942 2,682,845 Casas-Ro bert et a1. July 6, 1954 2,684,649 Scarpa July 27, 1954 2,693,778 Harris Nov. 9, 1954 2,757,626 Fujita Aug. 7, 1956 2,832,302 Gegauf Apr. 29, 1958 2,833,233 DAmico May 6, 1958 2,906,219 Vigorelli Sept. 29, 1959 FOREIGN PATENTS 19,184 Great Britain of 1908 1,095,914 France Dec. 29, 1954 1,096,140 France Dec. 29, 1954 

